Barefoot Running 101

To shed or not to shed the shod: What the experts say

Thursday, April 7, 2011, 12:00 am

You’ve read about it. You’ve seen it on the national news. You’ve been barraged with advertisements for it. You may have even tried it. Barefoot running has turned into a movement of sorts, with zealots and dissenters shouting from every angle. Both the pro-shoe and pro-barefoot camps have claimed the other is the culprit of all running injuries. If you’re an injured shod runner, it’s the shoe’s fault. If you’re an injured barefoot runner, blame the lack of footwear or barely-there footwear. Interestingly, most experts on the subject call for modesty in our opinions and patience as they continue to research and gather evidence.

Dr. Daniel Lieberman, Professor of Human Evolutionary Biology at Harvard and one of the leading researchers on barefoot running, insists we should ignore the extremes and consider the benefits of running with and without shoes. He laments the fact that his work has been oversimplified as a result of the media’s craving for eye-catching headlines.

“My research and what people have said about my research are two different things,” he explains. Although he has been made out to be the poster child for barefoot running, he says, “adopting a ‘this is good’ and ‘this is bad’ approach isn’t helping anybody.”

Washington D.C. podiatrist and running injury expert, Dr. Stephen Pribut, feels similarly slighted by a media who favors reporting magical injury cures over reality. Having been framed as an opponent of barefoot running, which he is not, he says “I don’t think there is a good reason to be dogmatic about it and saying ‘it’s good for everyone’ or ‘it’s bad for everyone.’ It’s, ‘whatever works best for you.’”

The existing research on the topic has elicited a number of interesting findings, but those who know what they are talking about, like Dr. Lieberman and Dr. Pribut, say there is still much work to be done. Thus far, the evidence doesn’t conclusively support ditching your shoes, nor does it support wearing super supportive footwear. For now, we will consider our individual circumstances and physiology, understand the existing research, and anxiously await the new evidence that is being worked on in labs across the world.

What We Know So Far

Although barefoot running exploded in the media in recent months, the concept is nothing new to many researchers and long-time barefoot runners. This has left the experts to combat misinformation produced by the spin-doctors from both camps. “People are just reacting to the word barefoot and not engaging with the science and what it means. There are people on both extremes making claims that have no evidence,” says Dr. Lieberman.

While his most recent study, published in Nature, has been used as a sort of advertisement for barefoot running, he continually works to clarify his findings. Co-author of the study, Adam Daoud, put it simply, saying, “our research is more concerned with the impact forces of heel versus forefoot striking.” What Dr. Lieberman and company have shown is that different footstrikes have different consequences when it comes to collision forces and mechanics, not that barefoot running is the injury cure-all.

In agreement with existing research, they demonstrated that barefoot runners tend to strike on their forefoot and midfoot, which elicits less force when coming in contact with the ground than heel strikers. Shod runners have been shown, more often than not, to be heel strikers, which means more pounding. In addition to the added impact forces, heel striking is said to mess with kinematic alignment by encouraging overstriding. “The problem is that you reach out too far with your foot and that can cause all sorts of problems,” says Dr. Pribut. That, in turn, causes that exaggerated impact with the ground, and as another study showed, longer contact with the ground.

Just as many of the elite-level coaches believe, what you wear on your feet takes a back seat to training and form every time. “If you run in alignment, you have a forefoot strike,” explains Dr. Lieberman. When landing on the forefoot or midfoot, runners tend to flex their knees, hips, and ankles, allowing them to land more softly, as opposed to locking the knee and hitting with the heel. In his research, Dr. Lieberman also found that when a runner forefoot strikes, the foot is the only part of the body that stops at the moment of collision, which is 1-1.5 percent of body weight. This is in comparison to heel striking, which causes the knee and below to stop at impact with the ground, comprising 6-8% of body weight.

Herein lies the interesting part: You can be a forefoot striker who wears shoes and get the same benefits as a forefoot striker who runs barefoot. It just so happens that runners tend to do it instinctively when they are barefoot because they don’t have the added heel cushioning of a shoe. Daoud echoes this point, saying, “running with a barefoot style — forefoot striking — in shoes is a viable option, though far less flashy and noticeable,” he says. There in lies the origination of the excitement over barefoot running. With well over 50 percent of runners suffering from injuries each year, a report on a universal remedy for running injuries is far more interesting than a discovery about running style.

A Call for Research

Interestingly, no research has yet to even look at the relationship between impact forces and injuries. While intuitively it makes sense that the harder you hit the ground, the more damage that is done, there is no evidence to prove it. It has been hypothesized that future research may simply show a trade-off of injuries. Perhaps forefoot strikers have a lower incidence of injuries related to collision, like stress fractures and shin splints, but are at greater risk for Achilles issues.

Despite the ever-changing field of shoe technology, running injuries are said to have remained the same for the last 30 years. It is important to consider, however, that the running population is far different than it was in the 1970s and 1980s. Runners have gone from being an exclusive elite group to an incredibly varied demographic. This is apparent in marathon statistics, which show the average finishing times are over an hour slower than they once were. Dr. Tucker points out that thirty years ago, there were few marathoners who finished marathons in over 5 hours.

“These people may be more prone to injuries,” he says. “The fact that injury rates are the same is in fact a positive thing, because without the shoes, perhaps the prevalence of injuries would be 30 percent higher.” To be sure, recent research published in the American Journal of Sports Medicine shows that wearing motion-control shoes, the antithesis of being barefoot, decreases fatigue in the lower legs for excessive rearfoot pronators by stabilizing the muscle activation pattern.

With injury prevention research touting the benefits of both shod and unshod running methods, it will likely come down to a debate about running form. Dr. Lieberman is currently working on research in hopes of showing that forefoot and midfoot striking will at least reduce injuries, but even still, emphasizes that there is no panacea to making running a pain-free activity.

If It Ain’t Broke

Both the academic and anecdotal evidence points to change as the largest injury risk factor in the sport of running. “If things have been going well with no injuries, there’s no reason to change what you’re doing,” says Dr. Pribut. If you’re contentedly running barefoot, in flats, stability shoes, or combat boots, keep doing what you’re doing.

Research done by Dr. Benno Nigg at the University of Calgary suggests that whatever you do, especially if it is done gradually, the body will make modifications. His research presents the idea of “muscle tuning,” showing that the soft tissues adapt, regardless of what you have on your feet. Dr. Tucker still contends, “the body doesn’t initially respond well to new stress, unless that stress is managed, which usually isn’t in cases like this.” He refers to the zeal with which many runners responded to the idea of shedding the shod and going barefoot. While he states he is not anti-barefoot, he calls runners to exercise patience with the transition.

“People get so excited about barefoot running and they rush out, buy Vibrams and hurt themselves,” ventures Dr. Lieberman. “If you’ve been running one style all of your life, you can’t just suddenly snap your fingers and become a different kind of runner. It takes work, training, and practice.”

What the Experts Do

Adding to the legitimacy of their expertise and opinions on the topic is the fact that many of the authorities are runners themselves. While Dr. Pribut runs mostly in shoes, he enjoys barefoot running on the beach and on grass, saying that he stays away from un-shod concrete and pavement running.

Dr. Lieberman transitioned to some barefoot running over a five-month period. A lifelong heel striker in high-cushioned shoes, he now wears minimal shoes, such as racing flats, and sometimes no shoes at all in non-winter months. His connection with barefoot running seems to be more spiritual than anything else, saying that it is a back-to-basics type of experience. The evolutionary biologist still contends, “you could say that helmets got in the way of evolution and I’d still wear a helmet when I ride a bike.”

Although he was immersed in the footstrike research while running at Harvard, Daoud waited to change anything until his competitive days were finished. Post-graduation, he transitioned to doing more forefoot running over the course of several months, mixing that style in with his original form. “I listened to my body to know how much time during a run would be forefoot striking,” he says. “Eventually I got over the hump and was able to do significant distances forefoot striking without fatiguing my calf muscles and without soreness the following day.” He has experimented with barefoot running a few times, but has yet to make it a regular part of his training.

Dr. Tucker runs mostly in moderately cushioned shoes, with a lighter pair to do longer speed work and races, and an even lighter pair for short track sessions. He bought Vibram FiveFingers as a means of being able to legitimately comment on the barefoot phenomenon. “I find them fun to run in for short races, but I can’t get anything like the distance and time I want to,” he says. “If I run in them at all, it’s usually for 15 to 25 minutes as part of a warm-up before a main run.” He has tried running completely barefoot, but has trouble locating un-thorned surfaces to do much of it.

There you have it. Even the experts are on the fence. “We have to look for ways to solve problems and not just give one blanket answer,” explains Dr. Pribut. Dr. Lieberman agrees, saying, “all we can do and should do at this point is give people information on how this works and let them decide for themselves what they want to do.” So far, that information is more concerned with footstrike than footwear.

When asked if running barefoot is dangerous, Dr. Pribut laughs and responds, “I think sitting down is dangerous.” His point is that running and exercise is good for you in most forms. He adds, “if running barefoot works for you, I’m happy.”

“There’s no reason you can’t forefoot strike on Tuesday, heel strike on Wednesday, go barefoot on Thursday, and wear shoes on Friday,” says Dr. Lieberman. “Should you be afraid of barefoot running? No. Should you not run barefoot? Only if you don’t want to. Should you run barefoot? If you want to. Is it useful to try? I think so.”